Many kinds of removable band-type clamps or couplings (the terms being used interchangeably throughout) for pipes exist in the art. It is noted that throughout the specification and claims, the term “pipe” encompasses any kind of generally cylindrical object.
For example, one commercially available type of pipe coupling has an annular seal clamp housing. Clamp members are positioned face to face and a tightening element is tightened to press an annular seal (annular elastomeric band) against the outside of the pipe inserted through the seal clamp housing. This type of clamp is particularly useful for pipe repair applications, such as the pipe repair clamp described in U.S. Pat. No. 6,830,268 to Krausz, the disclosure of which is incorporated herein by reference. The present invention is not limited to these pipe clamps, however.
Initially one end of the annular seal is typically secured to the annular clamp housing and the other end is left loose, unattached to the clamp housing. This is important because when the coupling is tightened against the pipe, the ends of the annular seal abut against each other. The free end of the seal allows the seal to move and expand radially about the pipe as the coupling is tightened, so that the seal always smoothly and uniformly presses against and around the pipe. If both ends of the seal were fixed to the clamp housing, the seal would be prevented from expanding uniformly radially about the pipe as the coupling is tightened. Rather the seal would bunch up, become folded or kinked, or otherwise deform, and would not smoothly and uniformly press against and around the pipe.
However, the free end of the seal can cause another problem. When initially placing the coupling about the pipe, the free end of the seal can hang loosely out of the annular seal clamp housing. It can be cumbersome for some installers to hold the free end of the seal in the housing while at the same time placing the coupling around the pipe.